#!/bin/bash

# Deployment script for Wilcon Client Dashboard

# --- Configuration ---
AGENT_USER="agent_user"
SERVICE_NAME="wilcon-agent"
BACKEND_PORT="8080"
BACKEND_SCRIPT="wilcon.py"
FRONTEND_FILE="index.html"

# --- Functions ---
usage() {
    echo "Usage: $0 <target_user> <target_ip> [target_path]"
    echo "  <target_user>: Username on the target device (e.g., 'ubuntu', 'pi')."
    echo "  <target_ip>: IP address or hostname of the target device."
    echo "  [target_path]: Optional. Full path on the target device where the project will be deployed. "
    echo "                 Defaults to '/opt/wilcon_agent'."
    exit 1
}

setup_ssh_key() {
    echo "--- Setting up SSH Key for passwordless access ---"
    # Check if ssh-keygen exists
    if ! command -v ssh-keygen &>/dev/null; then
        echo "Error: ssh-keygen not found. Please install OpenSSH client utilities."
        exit 1
    fi

    # Check if ssh-copy-id exists
    if ! command -v ssh-copy-id &>/dev/null; then
        echo "Error: ssh-copy-id not found. Please install OpenSSH client utilities (often in 'openssh-client' or 'ssh-client' package)."
        exit 1
    fi

    # Check if SSH key pair exists
    if [ ! -f "$HOME/.ssh/id_rsa.pub" ]; then
        echo "   SSH key pair not found. Generating new SSH key..."
        ssh-keygen -t rsa -b 4096 -f "$HOME/.ssh/id_rsa" -N "" # -N "" for no passphrase
        if [ $? -ne 0 ]; then
            echo "Error: Failed to generate SSH key. Aborting."
            exit 1
        fi
        echo "   Local SSH key generated."
    else
        echo "   Local SSH key pair already exists."
    fi

    # Check if the key is already authorized on the target device, and copy it if not.
    if ssh -q -o BatchMode=yes -o ConnectTimeout=5 "$TARGET_USER@$TARGET_IP" exit 2>/dev/null; then
        echo "   SSH key is already authorized on the target device. Skipping copy."
    else
        echo "   Copying public key to $TARGET_USER@$TARGET_IP... (You may be prompted for the password for '$TARGET_USER' on '$TARGET_IP')"
        ssh-copy-id "$TARGET_USER@$TARGET_IP"
        if [ $? -ne 0 ]; then
            echo "Error: Failed to copy SSH key. Please ensure SSH is enabled and the password is correct."
            exit 1
        fi
        echo "   SSH key copied successfully."
    fi
    echo ""
}

check_target_online() {
    echo "Checking if target device $TARGET_IP is online..."
    # Ping the target IP 3 times with a 1-second timeout per ping
    if ping -c 3 -W 1 "$TARGET_IP" &>/dev/null; then
        echo "   Target device is online."
    else
        echo "Error: Target device $TARGET_IP appears to be offline or unreachable."
        echo "Please ensure the device is powered on, connected to the network, and accessible via SSH."
        exit 1
    fi
    echo ""
}

# --- Main Script ---

# Check arguments
if [ -z "$1" ] || [ -z "$2" ]; then
    usage
fi

TARGET_USER="$1"
TARGET_IP="$2"
DEFAULT_TARGET_PATH="/opt/wilcon_agent"
TARGET_PATH="${3:-$DEFAULT_TARGET_PATH}"

echo "--- Starting Deployment ---"
echo "Target User: $TARGET_USER"
echo "Target IP:   $TARGET_IP"
echo "Target Path: $TARGET_PATH"
echo ""

# Set up SSH key for passwordless access
setup_ssh_key

# Check if the target device is online before proceeding
check_target_online

# 1. Generate requirements.txt on the local machine
echo "1. Generating requirements.txt..."
if [ -d "venv" ]; then
    source venv/bin/activate
    pip freeze >requirements.txt
    deactivate
else
    echo "Warning: 'venv' not found. Assuming dependencies are globally installed or already in requirements.txt."
    pip freeze >requirements.txt 2>/dev/null || echo "Could not generate requirements.txt. Ensure pip is installed."
fi
if [ ! -f "requirements.txt" ]; then
    echo "Error: requirements.txt could not be created. Aborting."
    exit 1
fi
echo "   requirements.txt generated."
echo ""

# 2. Prepare target directory on the remote host
echo "2. Preparing target directory on $TARGET_IP..."
echo "   This may ask for the sudo password for '$TARGET_USER' to create/access '$TARGET_PATH'."
REMOTE_DIR_PREP_COMMAND="
    set -e
    echo 'Remote: Attempting to create directory $TARGET_PATH...'
    sudo mkdir -p '$TARGET_PATH'
    echo 'Remote: Attempting to set ownership for $TARGET_PATH...'
    sudo chown -R $TARGET_USER:\$(id -gn $TARGET_USER) '$TARGET_PATH'
    echo 'Remote: Directory preparation commands completed.'
"
if ! ssh -t "$TARGET_USER@$TARGET_IP" "$REMOTE_DIR_PREP_COMMAND"; then
    echo "Error: Failed to create or set permissions for '$TARGET_PATH' on the target device."
    echo "Please ensure user '$TARGET_USER' has sudo privileges and the path is correct."
    exit 1
fi
echo "   Target directory prepared successfully."
echo ""

# 3. Transfer project files to the target device
echo "3. Transferring project files to $TARGET_USER@$TARGET_IP:$TARGET_PATH..."
# Using tar to pipe files over SSH, which is more robust than 'scp -r .'
tar cf - --exclude=venv . | ssh "$TARGET_USER@$TARGET_IP" "
    set -e
    echo 'Remote: Navigating to $TARGET_PATH...'
    cd '$TARGET_PATH'
    echo 'Remote: Starting file extraction...'
    tar xf -
    echo 'Remote: File extraction completed.'
"
if [ $? -ne 0 ]; then
    echo "Error: File transfer failed. Check SSH connectivity, permissions, and if 'tar' is installed on both systems."
    exit 1
fi
echo "   Files transferred successfully."
echo ""

# 4. Make installation script executable on the target device
echo "4. Making installation script executable on target..."
ssh "$TARGET_USER@$TARGET_IP" "chmod +x '$TARGET_PATH/install_service.sh'"
if [ $? -ne 0 ]; then
    echo "Error: Failed to make install_service.sh executable."
    exit 1
fi
echo "   Installation script is now executable."
echo ""

echo "--- Deployment Complete! ---"
echo "Project files have been successfully deployed to $TARGET_IP:$TARGET_PATH"
echo ""
echo "Next Step: Log in to the target device and run the installation script:"
echo "  ssh $TARGET_USER@$TARGET_IP"
echo "  cd $TARGET_PATH"
echo "  sudo ./install_service.sh"